Heraclitus of Ephesus was the founder of the Heraclitean School.

The Heraclitean School believed that the universe is in a state of constant flux and change.

Heraclitus meant by "flux" a continuous process of change.

Heraclitus believed that the underlying principle of the universe was Logos, which can be translated as "reason" or "order".

Heraclitus believed that opposites are in harmony with each other, and that this harmony is the source of all change.

Heraclitus believed that the soul is made up of fire, and that when the body dies, the fire is extinguished.

The fragment "Ignorance is bliss" is not attributed to Heraclitus.

Plato was influenced by the Heraclitean School, and his philosophy of Forms can be seen as a response to Heraclitus's philosophy of flux.

Heraclitus used the Achelous River as an example of constant change, saying that you cannot step into the same river twice.

Heraclitus believed that strife was the source of all change.

Heraclitus believed that the individual is a microcosm of the universe, and that the same laws that govern the universe also govern the individual.

Heraclitus believed that the best way to live was to live in accordance with nature.

Heraclitus believed that the ultimate fate of the universe was to be destroyed by fire.

Heraclitus wrote a book called "On Nature", which is now lost.